I was surprised to see compere come up as a rare word. I know it's not a 'true' English word but it's common in the UK. When there's a US v UK difference both words are usually classified in the same way (although I don't doubt that someone will inform me of instances where this isn't the case!)

We've had a couple of discussions of compere, in 2015 and in 2012. It is indeed a UK vs US matter, with some American forumites having never heard of the word. In the 2102 discussion TRex noted that emcee was one of the terms used in the US.

I'm not sure how well known emcee is outside North America, but quite possibly it should be reclassified as rare. Probably the reason the issue hasn't been raised before is that the word didn't appear in any puzzles before the 7-by-many was introduced.

I'm not sure that 'compere' (which according to Google NGram viewer is not completely unknown in the US) and 'MC / emcee' are entirely synonymous.For example, at the start of a boxing match, the person in the ring with a microphone ('On my left, in the blue corner all the way from......') is an MC, a 'Master of Ceremonies'. Nobody in UK would call him a 'compere', which normally refers to somebody introducing the acts in a variety show, in a theatre or on TV.

Also, over the last thirty years or so, anybody aspiring to be a rap artist has, it seems, been obliged to go by the adopted name of 'MC xyz' or whatever. Although I'm not sure if that usage is ever spelled 'emcee', it may have helped to make the word itself better known.

And then there's 'commere' (the word we ought to use if the compere is female), which, like 'compere', originally meant 'godparent' - much like Chaucer's 'gossib' ('godsib), which eventually gave us 'gossip'.

I think every Chi player would know what an MC is. The only question is, how many are aware that it is sometimes written emcee?

Emcee is certainly not as rare in Britain as compere is in the US. I can find examples in many British newspapers - Guardian, Telegraph, Times, Independent, etc. As far back as 1993 British magician Terry Seabrooke published a book called Beyond Compere: A Pocket Guide to being an Emcee.

People write emcee here in Australia too. Last year the Age used it in an article about the Granny Smith Festival Queen Quest. (A granny smith is a type of apple.) It has also been used in the Times of India, the Irish Times and the New Zealand Herald.

I'm leaving emcee as a common word for the time being. Its origin in the pronunciation of a pair of letters is neither here nor there - okay is a common word too.